The invention relates to the field of gliding sports and, more precisely, to the snow sport generally known as snowboarding. It relates more specifically to an element forming an interface plate intended to be inserted between the actual binding and the board, so as to optimize the transmission of the forces and the behavior of the board.
In a known way, snowboard bindings are mounted on the snowboard with a certain latitude for rotation, to allow the angle of the longitudinal mid-plane of the corresponding binding to be adjusted to that of the foot with respect to the longitudinal axis of the board.
Specifically, in order to be able to adopt the most ergonomical position possible, it may be necessary for the front and back feet to have a certain orientation with respect to the board.
This orientation may differ from the front foot with respect to the back foot, and may also vary according to the type of riding. Thus, in the freestyle type of riding, the orientation of the feet, and therefore of the binding, is further from the longitudinal axis of the board than it is for alpine riding in which the feet are closer to the longitudinal axis of the board.
Furthermore, there are two possible orientations of the foot with respect to the perpendicular to the longitudinal axis of the board.
Specifically, certain snowboarders prefer to have their left foot at the front end of the board. Surfers who ride in this way are known as xe2x80x9cregularxe2x80x9d.
Conversely, certain snowboarders prefer to have their right foot at the front end of the board. Such snowboarders are known as xe2x80x9cgoofyxe2x80x9d. As the back foot is generally more perpendicular to the longitudinal axis of the board than the front foot, it then follows that the binding may adopt an angle that varies widely depending on whether it is used by a xe2x80x9cgoofyxe2x80x9d snowboarder or a xe2x80x9cregularxe2x80x9d snowboarder.
Moreover, it has been found that the forces are generally exerted from the binding to the board and located essentially in the region of the extreme zones of the binding corresponding to the front of the foot in the case of frontside turns and corresponding to the back of the foot in the case of backside turns.
In other words, the forces are exerted in a way which is offset with respect to the edges according to the orientation of the binding with respect to the board.
The further the foot is away from the perpendicular, the more the thrust is exerted in a zone away from the edges, and therefore the less effective this thrust is.
A first problem that the invention sets out to solve is that of optimizing the location of the thrust exerted from the binding, regardless of the orientation of the binding with respect to the longitudinal axis of the board.
Moreover, in the most frequent case where the binding is not perpendicular to the longitudinal axis of the board, the two zones for transmitting thrust from the binding to the board, located at the front and at the back of the foot, are longitudinally offset with respect to the board. It then follows that the part of the binding located between these two thrust zones has a rigidity which adds to and combines with the intrinsic rigidity of the board.
This interference modifies the intrinsic mechanical strength characteristics of the board and causes it to diverge from its theoretical behavior. A modification such as this is detrimental to the ability of the board to withstand the forces.
Specifically, numerous instances of boards breaking at the extreme zones of the binding as a result of the appearance of excessive stress when bowing the board have, in particular, been observed.
Another problem that the invention sets out to solve is that of decoupling the binding with respect to the board and of reducing the influence of the mechanical rigidity of the binding on the intrinsic mechanical properties of the board.
The object of the invention is therefore to optimize the thrust exerted from the binding to the board while at the same time allowing a certain decoupling of rigidity of the binding and of the board, while remaining compatible with the latitude for adjustment of the orientation of the binding with respect to the longitudinal axis of the board, according to the various styles of riding and the various types of user.
The invention therefore relates to an interface plate intended to be inserted between a snowboard binding and the upper face of a snowboard.
This plate is noteworthy in that it comprises:
an essentially circular central zone through which the screws for attaching the binding to the board can pass;
two outer zones of a width smaller than the diameter of the central zone, arranged symmetrically with respect to the central zone, and of which the ends furthest from the central zone act as supports for diametrically opposed zones of the binding so as to transmit the forces exerted from the binding to the board only at said outer zones which are advantageously located near to the edges.
In other words, the plate according to the invention is intended to be arranged in such a way that these outer zones are as close as possible to the edges, which essentially corresponds to a position in which the interface plate has its longitudinal mid-plane perpendicular to the longitudinal axis of the board.
In that way, contact between the binding and the board is predominantly at these outer zones of the plate, which are located near to the edges.
The thrust exerted from the binding to the board is therefore mainly concentrated near the edges, which improves the precision and control of the snowboard.
Furthermore, by virtue of the characteristic plate, the mechanical influence of the binding on the board is essentially limited to a zone which is reduced in size in the longitudinal direction of the board. In that way, the impact that the rigidity of the binding has is relatively low when bowing the board. The latter therefore retains its intrinsic mechanical properties and its optimum behavior.
Depending on the orientation of the binding with respect to the board, the ends of the plate furthest from the central zone act as supports for diametrically opposed zones of the binding arranged on a diagonal with respect to the latter.
In other words, the interface plate remains fixed with respect to the board and the zones of contact of the plate with respect to the binding change according to the orientation of the binding with respect to the board. However, the force-transmission zones corresponding to the outer zones of the characteristic plate always remain near the edges regardless of the orientation of the binding.
The geometry of the plate is determined in such a way that the orientation of the binding can vary in a large range of angles, while overlapping the characteristic plate so as to enjoy the transmission of thrust near the edges.
According to another feature of the invention, the interface plate may be associated with a peripheral gasket arranged essentially vertically above the outer contour of the baseplate of the binding so as to prevent snow from penetrating under said baseplate.
This peripheral gasket may either be incorporated into the binding or alternatively may be an independent part, the position of which changes with the orientation of the binding.
This prevents snow from accumulating under the baseplate and, when frozen, forming a rigid block which would allow forces to be transmitted from the binding to the board outside of the favored zones that the outer zones of the plate constitute.
Advantageously in practice, the central zone may comprise a cylindrical protrusion arranged at its center and intended to collaborate with a complementary cylindrical opening formed for this purpose in the baseplate of the binding. In this case, the plate is more intended to be used with bindings which have a monolithic baseplate, which is pivoted in its entirety when the orientation of the binding is adjusted.
This pivoting therefore occurs above the characteristic interface plate, the protrusion of which acts as a fixed point.
Conversely, the characteristic plate may be used with another category of binding, in which the baseplate has, at its center, a recess designed to take an indexed disk mounted on the board through the characteristic plate, without the ability to rotate. In this scenario, the remainder of the baseplate of the binding is oriented with respect to this fixed central disk.
Advantageously in practice, the characteristic plate comprises through-holes for the passage of the binding attachment screws.
Moreover, it may prove advantageous to adjust the longitudinal position of the binding according to the ergonomics and to the optimum position desired by the user.
Such an adjustment, known as adjusting the stance, is obtained by virtue of the fact that the holes passing through the characteristic plate form widened slots so as to allow the plate to be shifted in translation with respect to the upper face of the board which has the tapped holes for attaching the binding.
In that way, when the user wishes to shift the position of the binding longitudinally, he shifts both the baseplate of the binding and the characteristic plate by translating these two elements in the direction of the widened slots.
Furthermore, in certain styles of riding, it may prove advantageous for the leg to have a certain orientation with respect to the vertical, particularly during freestyle riding. In this case, the characteristic plate may have upper and lower faces which form an angle of between two and eight degrees, offsetting the inclination or canting of the binding by this same amount with respect to the vertical.